Reconditioning Rocker Arm Mechanism; Changing Camshaft/Camshaft Gear; Valve Mechanism - Valtra 6000 Workshop Manual

21. Engine

2. Valve mechanism

A. Reconditioning rocker arm mechanism
1. Check the valve tappets, especially the contact surface
against the camshaft. Worn or damaged tappets should be
discarded.
2. Check the straightness of the pushrods by rolling them on
a surface table. Check also the spherical surfaces at the ends.
3. Dismantle and clean the rocker arm mechanism. Check the
shaft for wear and that the oilways are clean.
4. Check that the rocker arm bushings are not worn. Ensure
that the oil hole is positioned correctly when pressing in new
bushings. After pressing in the bushings they should be re-
amed to 19,990 ---20,010 mm. Where necessary grind the
rocker arm valve contact surface to the correct shape. Do not
grind more than necessary as the hardened layer is thin.
19,990...20,010
55
Model
6000-- 8750
1. 9. 1992
5. Fit the plug to the other end of the rocker arm shaft. Lubri-
cate the shaft and fit various parts in a correct order. Note the
correct position of the shaft and the bearing brackets. The split
side of the bracket and the shaft oil holes must be turned to
the valve side (see figure above). Fit the other end plug.
B. Changing camshaft/camshaft gear
1. Remove the inlet pipe between the turbocharger and the
induction manifold. Remove the valve cover and the breather
pipe. Remove the rocker arm mechanism.
2. Remove the radiator, cooling fan, alternator and the v ---belt.
3. Remove the crankshaft nut. Remove the V ---belt pulley in-
cluding the hub (on 620---engines the belt pulley must be
removed first).
4. Remove the timing gear casing cover (engine front cover).
5. Connect the pushrods in pairs, using o---rings or elastic
bands to prevent them from falling through.
Note! Do not connect the pushrods too tightly as this might
cause them to bend or snap.
Code Page
212 5
60˚